Systems and methods for treating a vessel using focused force

ABSTRACT

A device for introduction into a vessel including a main elongated element having a main elongated element proximal end and a main elongated element distal end, a balloon positioned at the main elongated element distal end, and a core wire attached to the device at a core wire attachment point and including an internal core wire portion positioned in the main elongated element and an external core wire portion positioned distally with respect to the internal core wire portion and positioned in parallel relation and external to the balloon.

CROSS REFERENCES TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.11/746,682, filed May 10, 2007, which is a continuation-in-part of U.S.patent application Ser. No. 11/431,918, filed May 11, 2006, and acontinuation-in-part of International Patent Application No.PCT/IL2006/001150, filed Oct. 3, 2006, each of which aforementionedapplication is incorporated by reference in its entirety into thisapplication.

FIELD OF THE INVENTION

The present invention relates to systems and methods for treating avessel using focused force, to aid in cracking of difficult lesions.

BACKGROUND OF THE INVENTION

Balloon dilatation catheters are used to treat lesions in vessels.However, difficulties are encountered in navigating tortuous anatomy andsafely crossing very tight lesions. Moreover, some lesions are difficultto crack using just a balloon, and require a focused force to enablecracking of the lesion at safe inflation pressures.

An example of a system used to provide enhanced force is disclosed inU.S. Pat. No. 6,394,995 to Solar et al. Disclosed therein is a systemhaving a flexible advancement member with a tracking member slidableover a guidewire, and a balloon having a distal end attached to thetracking member. However, this type of system provides limited focusedforce, does not address bifurcation lesions, and lacks pushability andmaneuverability.

It is therefore an object of the present invention to provide enhancedballoon dilatation catheter systems and methods with improvedmaneuverability and multiple treatment options.

SUMMARY OF THE INVENTION

According to one aspect of the present invention, there is provided adevice for introduction into a vessel. The device includes a mainelongated element having a main elongated element proximal end and amain elongated element distal end, a balloon positioned at the mainelongated element distal end, an auxiliary elongated element having anauxiliary elongated element proximal end and an auxiliary elongatedelement distal end, the auxiliary elongated element distal endpositioned proximal to the balloon, and a core wire including aninternal core wire portion positioned within the main elongated elementand attached to the main elongated element at a core wire attachmentpoint and an external core wire portion positioned distally with respectto the internal core wire portion, the external core wire portionexternal to and running alongside the balloon.

According to features of the present invention, in some embodiments adistal connecting element is positioned at a distal end of the balloonand may be rotationally spaced from or aligned with the auxiliaryelongated element. In other embodiments, a fixed wire is positioned atthe distal end of the balloon. The device may be over-the-wire or rapidexchange, as these terms are known in the art, or a combination thereof.In some embodiments, the external core wire has a coil for preventingslippage of the balloon with respect to the lesion. In some embodiments,an occlusion balloon is positioned proximal to the auxiliary elongatedelement distal end.

In accordance with additional aspects of the present invention, there isprovided a device for introduction into a vessel. The device includes amain elongated element having a main elongated element proximal end anda main elongated element distal end, a balloon positioned at the mainelongated element distal end, an auxiliary elongated element having aproximal and a distal end, the auxiliary elongated element distal endpositioned proximal to the balloon, and a distal connecting elementpositioned at a distal end of the balloon, wherein the distal connectingelement is at a rotational distance from the auxiliary elongatedelement.

In accordance with additional aspects of the present invention, there isprovided a method for treating a vessel. The method includes providing adevice having a main elongated element, a balloon at a distal end of thedevice, an auxiliary elongated element wherein a distal end of theauxiliary elongated element is proximal to the balloon, and a wireattached to the device and positioned alongside the balloon and on anopposite side of the balloon as the auxiliary elongated element and adistal connecting element at a distal end of the balloon, inserting atracking guidewire into the vessel, backloading the tracking guidewireinto the distal connecting element, advancing the device over thetracking guidewire until the distal end of the device is adjacent to thelesion, advancing a second guidewire through the auxiliary elongatedelement, and inflating the balloon so as to push at least the attachedwire and the tracking guidewire against different sides of a lesion inthe vessel.

Unless otherwise defined, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this invention belongs. Although methods and materialssimilar or equivalent to those described herein can be used in thepractice or testing of the present invention, suitable methods andmaterials are described below. In case of conflict, the patentspecification, including definitions, will control. In addition, thematerials, methods, and examples are illustrative only and not intendedto be limiting.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and further advantages of the present invention may be betterunderstood by referring to the following description in conjunction withthe accompanying drawings in which:

FIG. 1A is a schematic illustration of a system for treatment of avessel, in accordance with embodiments of the present invention;

FIGS. 1B-1D are cross-sectional illustrations of the system of FIG. 1A;

FIG. 1E is a perspective illustration of the system of FIG. 1A;

FIG. 1F is a schematic illustration of the system of FIG. 1A, with anocclusion balloon;

FIG. 1G is a cross-sectional illustration of the system of FIG. 1F;

FIG. 2 is a schematic illustration of a system for treatment of avessel, in accordance with other embodiments of the present invention;

FIG. 3 is a schematic illustration of a system for treatment of avessel, in accordance with yet additional embodiments of the presentinvention;

FIG. 4 is a schematic illustration of a system for treatment of avessel, in accordance with yet additional embodiments of the presentinvention;

FIGS. 5A and 5B are illustrations of a core Wire, in accordance withembodiments of the present invention;

FIGS. 6A-6D are cross-sectional illustrations of a distal portion of thesystems of FIGS. 1-4;

FIGS. 7A-7F are schematic illustrations of the steps of a method oftreating a vessel, in accordance with embodiments of the presentinvention;

FIGS. 8A-8C are schematic illustrations of the steps of a method oftreating a vessel, in accordance with additional embodiments of thepresent invention;

FIGS. 9A-9C are schematic illustrations of the steps of a method oftreating a vessel, in accordance with additional embodiments of thepresent invention; and

FIGS. 10A-10C are schematic illustrations of the steps of a method oftreating a bifurcated vessel, in accordance with additional embodimentsof the present invention.

It will be appreciated that for simplicity and clarity of illustration,elements shown in the drawings have not necessarily been drawnaccurately or to scale. For example, the dimensions of some of theelements may be exaggerated relative to other elements for clarity orseveral physical components may be included in one functional block orelement. Further, where considered appropriate, reference numerals maybe repeated among the drawings to indicate corresponding or analogouselements. Moreover, some of the blocks depicted in the drawings may becombined into a single function.

DETAILED DESCRIPTION

In the following detailed description, numerous specific details are setforth in order to provide a thorough understanding of the presentinvention. It will be understood by those of ordinary skill in the artthat the present invention may be practiced without these specificdetails. In other instances, well-known methods, procedures, componentsand structures may not have been described in detail so as not toobscure the present invention.

The present invention is directed to systems and methods for treatmentof a vessel using focused force. The principles and operation of asystem and methods according to the present invention may be betterunderstood with reference to the drawings and accompanying descriptions.

Before explaining at least one embodiment of the present invention indetail, it is to be understood that the invention is not limited in itsapplication to the details of construction and the arrangement of thecomponents set forth in the following description or illustrated in thedrawings. The invention is capable of other embodiments or of beingpracticed or carried out in various ways. Also, it is to be understoodthat the phraseology and terminology employed herein are for the purposeof description and should not be regarded as limiting.

It is appreciated that certain features of the invention, which are, forclarity, described in the context of separate embodiments, may also beprovided in combination in a single embodiment. Conversely, variousfeatures of the invention, which are, for brevity, described in thecontext of a single embodiment, may also be provided separately or inany suitable subcombination.

Reference is now made to FIGS. 1A and 1E, which are a schematic andperspective illustration, respectively, of a system 10 for treatment ofa vessel, in accordance with embodiments of the present invention.System 10 includes a main elongated element 12 having a proximal end 14and a distal end 16. In some embodiments of the present invention, mainelongated element 12 is a catheter shaft. A balloon 24 is positioned atdistal end 16 of main elongated element 12. Balloon 24 can be comprisedof a variety of diameters, ranging from 1.25-10.0 mm, for example, and avariety of lengths, ranging from 10 mm to 30 cm, for example. Longballoons may be particularly useful for treating peripheral lesions,which often have long diseased portions. System 10 further includes anauxiliary elongated element 18 configured to receive a guidewire 48therethrough. Auxiliary elongated element 18 has a proximal end 20 witha proximal exit point 21 for guidewire 48 and a distal end 22 with adistal exit point 23 for guidewire 48. In some embodiments, at least aportion of auxiliary elongated element 18 is positioned within mainelongated element 12 so as to reduce the outer profile of system 10.Distal end 22 of auxiliary elongated element 18 is proximal to balloon24 such that guidewire 48, when positioned through auxiliary elongatedelement 18, exits distal exit point 23 and runs alongside and externalto balloon 24. This configuration provides for a focused force elementalongside balloon 24, as will be described further hereinbelow. In someembodiments, such as the one shown in FIGS. 1A and 1E, auxiliaryelongated element 18 runs along the length of main elongated element 12to a proximal guidewire port 50. This configuration provides anover-the-wire type of configuration. In one embodiment, guidewire 48positioned through distal exit point 23 forms a crotch point 46 at ornear a proximal end of balloon 24. The presence of a crotch point may beuseful, for example, for anchoring system 10 within a side branch toavoid slippage within the vessel to be treated, or to provide forprecise positioning of system 10 at a bifurcation.

In some embodiments, main elongated element 12 is stiffer proximallythan distally. This may be accomplished, for example, by using a metalhypotube in the proximal portion and a polymer or other flexiblematerial in the distal portion. This configuration provides moreflexibility at the distal end to allow for easier maneuverabilitythrough tortuous vessels, while maintaining rigidity at a proximal endfor pushability. However, if the distal portion of main elongatedelement 12 is too flexible, it will be difficult to push through thevessels. Thus, system 10 further includes a core wire 28, which providesenhanced pushability of system 10 without significantly reducing theflexibility of system 10. Core wire 28 is provided in the flexibleportion, and may terminate at the stiff portion when no longer neededfor rigidity. In other embodiments, main elongated element 12 isrelatively flexible along all or most of its length, by using a flexiblepolymer or other flexible material to form main elongated element 12. Inthese embodiments, core wire 28 may run along an entire length of mainelongated element 12 and may vary in diameter along the length so as toprovide increased rigidity at proximal end 14. In some embodiments, theflexible shaft may also be braided or otherwise strengthened to providesufficient rigidity.

In embodiments of the present invention, core wire 28 has a portionpositioned within main elongated element 12, referred to herein asinternal core wire portion 30, and a portion positioned external to mainelongated element 12, referred to herein as external core wire portion32. Internal core wire portion 30 is proximal to external core wireportion 32, and is attached to main elongated element 12 at an internalcore wire attachment point 44. For embodiments wherein main elongatedelement 12 is comprised of a relatively flexible distal portion and arelatively rigid proximal portion, internal core wire attachment point44 is located at an interface between the stiff proximal portion and theflexible distal portion, for example, a distal end of the hypotube. Inembodiments wherein main elongated element is mostly or completelycomprised of flexible material, internal core wire attachment point 44is located at proximal end 14 of system 10. However, it should bereadily apparent that internal core wire attachment point 44 may belocated at any location along the length of main elongated element 12.Moreover, multiple internal core wire attachment points 44 may beincluded. At a location proximal to balloon 24, internal core wireportion 30 exits main elongated element 12 and becomes external corewire portion 32. This location is referred to herein as a core wire exitpoint 42. In one embodiment, core wire exit point 42 is at a distal endof main elongated element 12. In other embodiments, core wire exit point42 is at other locations along main elongated element 12 (but in mostcases proximal to balloon 24). Distal to core wire exit point 42,external core wire portion 32 is positioned alongside balloon 24, and adistal end of external core wire portion 32 is attached to a distal tip25 of balloon 24. Several attachment or bonding locations providetransmission of forces through the length of the catheter, and thusenhance overall torquability and rotatability. In particular, bondingcan be done at any or all of the following locations: at distal tip 25of balloon 24, at core wire exit point 42, and at internal core wireattachment point 44. Additional attachment points may be included aswell. It should be noted that the use of an internal core wire makes itpossible to have a longer flexible (polymeric or other) portion or evena completely flexible shaft, enhancing overall flexibility of system 10.

System 10 further includes a distal connecting element 38 at distal tip25 of balloon 24. Distal connecting element 38 is a short rail, rangingin length from 2-20 mm, and may be bonded to distal tip 25 such that theproximal end of distal connecting element 38 is distal to balloon 24. Athree-way bond may be used to attach distal connecting element 38,balloon 24 and external core wire portion 32, all together. Distalconnecting element 38 may be tapered toward its distal end to facilitatepassage through tight stenoses. Distal connecting element 38 ispositioned at a rotational distance from auxiliary elongated element 18and from external core wire portion 32, and is configured to hold atracking guidewire 49 therethrough. In some embodiments, distalconnecting element 38, auxiliary elongated element 18 and external corewire portion 32 are positioned approximately 120° from one another. Inother embodiments, other rotational distances may be used, such thatthere is some rotational separation between them. In this way, guidewire48, tracking guidewire 49 and core wire 32 may all lie alongside balloon24 at different rotational positions along balloon 24 when balloon 24 isin its expanded state. Although the separations between guidewire 48,tracking guidewire 49 and core wire 32 are not required to be anyspecific amounts, it should be apparent that the distances between themshould be sufficient to provide separate wires alongside severaldifferent areas of balloon 24. Each of these wires can then provide afocused force to help crack difficult lesions, as will be explainedfurther hereinbelow. It should be noted that in some embodiments,guidewire 48 and tracking guidewire 49 may be of different sizes.

Reference is now made to FIGS. 1B-1D, which are cross-sectionalillustrations of system 10 shown at section A-A, in accordance withseveral embodiments of the present invention. As shown in FIG. 1B, aninterior portion of main elongated element 12 serves as an inflationlumen 26, providing fluid communication between an inflation port 52located at proximal end 14 of main elongated element 12 and balloon 24located at distal end 16 of main elongated element 12. In someembodiments, a portion of the interior of main elongated element 12 issectioned off for use as inflation lumen 26, as shown in FIG. 1C and inFIG. 1D, wherein only the sectioned off inflation lumen 26 is in fluidcommunication with inflation port 52. Auxiliary elongated element 18 ispositioned within main elongated element along an edge thereof. Thecross-sectional views of FIGS. 1B-1D show auxiliary elongated element 18with guidewire 48 positioned therein. Internal core wire portion 30 ispositioned within main elongated element 12. In some embodiments, asshown in FIGS. 1B and 1C, internal core wire portion 30 is positionedalong an edge of main elongated element 12. In other embodiments, asshown in FIG. 1D, internal core wire portion 30 is positioned in acenter of main elongated element 12. It should be readily apparent,however, that at core wire attachment point 44 and at core wire exitpoint 42, the core wire is in contact with or close proximity to an edgeof main elongated element 12. Tracking guidewire 49 is shown external tomain elongated element 12.

Reference is now made to FIGS. 1F and 1G, which are schematic andcross-sectional illustrations of system 10 further including anocclusion balloon 54. Occlusion balloon 54 is positioned around mainelongated element 12 and is proximal to auxiliary element distal exitpoint 23. Occlusion balloon 54 may be used to temporarily occlude bloodflow proximal to occlusion balloon 54, and to enable introduction of anitem or a substance into the vessel at the lesion site via auxiliaryelongated element 18. In some embodiments, the item is a treatmentdevice, such as a guidewire with an ablation tip or any other treatmentdevice. In some embodiments, the substance is contrast media. In otherembodiments, the substance is a therapeutic drug or medicated solution.In some embodiments, multiple ports 19 may be included on auxiliaryelongated element 18, distal to occlusion balloon 54. These multipleports 19 may enable spraying of a substance such as contrast media,drugs, medicated solutions, etc. Reference is now made to FIG. 2, whichis a schematic illustration of system 10, wherein distal connectingelement 38 is aligned with auxiliary elongated element 18, such thatguidewire 48 may be positioned through distal connecting element 38 andfurther through auxiliary elongated element 18, and out throughauxiliary elongated element proximal exit point 21. Thus, only oneguidewire is used in the configuration shown in FIG. 2. This designprovides a single guidewire enclosure split into two sections—one at thedistal end and one at the proximal end of balloon 24—in order to reducethe profile of system 10 in the vicinity of balloon 24 duringintroduction of system 10 into a vessel. Guidewire 48, while positionedwithin distal connecting element 38 and auxiliary elongated element 18,can serve as a focused force to help crack difficult lesions and mayalso be used as a tracking guidewire for advancing system 10 into thevessel.

Reference is now made to FIG. 3, which is a schematic illustration of asystem 100, in accordance with additional embodiments of the presentinvention. System 100 includes a main elongated element 112 having aproximal end 114 and a distal end 116. In some embodiments of thepresent invention, main elongated element 112 is a catheter shaft. Aballoon 124 is positioned at distal end 116 of main elongated element112. Balloon 124 can be comprised of a variety of diameters, rangingfrom 1.25-10.0 mm, for example, and a variety of lengths, ranging from10 mm to 30 cm, for example. Long balloons may be particularly usefulfor treating peripheral lesions, which often have long diseasedportions. System 100 further includes an auxiliary elongated element 118configured to receive a guidewire 48 therethrough. Auxiliary elongatedelement 118 has a proximal end 120 with a proximal exit point 121 forguidewire 48 and a distal end 122 with a distal exit point 123 forguidewire 48. In some embodiments, at least a portion of auxiliaryelongated element 118 is positioned within main elongated element 112 soas to reduce the outer profile of system 100. Distal end 122 ofauxiliary elongated element 118 is proximal to balloon 124 such thatguidewire 48, when positioned through auxiliary elongated element 118,exits distal exit point 123 and runs alongside and external to balloon124. This configuration provides for a focused force element alongsideballoon 124, as will be described further hereinbelow. In someembodiments, such as the one shown in FIG. 3, auxiliary elongatedelement 118 is relatively short, extending 5-30 cm, and in someembodiments approximately 20 cm. This configuration enables rapidexchange in cases when system 100 may need to be retracted and adifferent device reinserted over guidewire 48. In one embodiment,guidewire 48 positioned through distal exit point 123 forms a crotchpoint 146 at or near a proximal end of balloon 124. The presence of acrotch point may be useful, for example, for anchoring system 100 withina side branch to avoid slippage within the vessel to be treated, or toprovide for precise positioning of system 100 at a bifurcation.

In some embodiments, main elongated element 112 is stiffer proximallythan distally. This may be accomplished, for example, by using a metalhypotube in the proximal portion and a polymer or other flexiblematerial in the distal portion. This configuration provides moreflexibility at the distal end to allow for easier maneuverabilitythrough tortuous vessels, while maintaining rigidity at a proximal endfor pushability. However, if the distal portion of main elongatedelement 112 is too flexible, it will be difficult to push through thevessels. Thus, system 100 further includes a core wire 128, whichprovides enhanced pushability of system 100 without significantlyreducing the flexibility of system 100. Core wire 128 is provided in theflexible portion, and may terminate at the stiff portion when no longerneeded for rigidity. In other embodiments, main elongated element 112 isrelatively flexible along all or most of its length, by using a flexiblepolymer or other flexible material to form main elongated element 112.In these embodiments, core wire 128 may run along an entire length ofmain elongated element 112 and may vary in diameter along the length soas to provide increased rigidity at proximal end 114. In someembodiments, the flexible shaft may also be braided or otherwisestrengthened to provide sufficient rigidity.

In embodiments of the present invention, core wire 128 has a portionpositioned within main elongated element 112, referred to herein asinternal core wire 130, and a portion positioned external to mainelongated element 112, referred to herein as external core wire 132. Forembodiments wherein main elongated element 112 is comprised of arelatively flexible distal portion and a relatively rigid proximalportion, internal core wire attachment point 144 is located at aninterface between the stiff proximal portion and the flexible distalportion, for example, a distal end of the hypotube. In embodimentswherein main elongated element is mostly or completely comprised offlexible material, internal core wire attachment point 144 is located atproximal end 114 of system 100. However, it should be readily apparentthat internal core wire attachment point 144 may be located at anylocation along the length of main elongated element 112. Moreover,multiple internal core wire attachment points 144 may be included. At alocation proximal to balloon 124, internal core wire 130 exits mainelongated element 112 and becomes external core wire 132. This locationis referred to herein as a core wire exit point 142. In one embodiment,core wire exit point 142 is at a distal end of main elongated element112 (but in most cases proximal to balloon 124). In other embodiments,core wire exit point 142 is at other locations along main elongatedelement 112. Distal to core wire exit point 142, external core wire 132is positioned alongside balloon 124, and a distal end of external corewire 132 is attached to a distal tip 125 of balloon 124. Severalattachment or bonding locations provide transmission of forces throughthe length of the catheter, and thus enhance overall torquability androtatability. In particular, bonding can be done at any or all of thefollowing locations: at a distal tip of balloon 124, at core wire exitpoint 142, and at internal core wire attachment point 144. Additionalattachment points may be included as well. It should be noted that theuse of an internal core wire makes it possible to have a longer flexible(polymeric or other) portion or even a completely flexible shaft,enhancing overall flexibility of system 100.

System 100 further includes a distal connecting element 138 at distaltip 125 of balloon 124. Distal connecting element 138 is a short rail,extending 2-20 mm, and in some embodiments approximately 10 mm, and maybe bonded to distal tip 125 such that the proximal end of distalconnecting element 138 is distal to balloon 124. A three-way bond may beused to attach distal connecting element 138, balloon 124 and core wire132 all together. Distal connecting element 138 may be tapered towardits distal end to facilitate passage through tight stenoses. Distalconnecting element 138 is aligned with auxiliary elongated element 118,such that guidewire 48 may be positioned through distal connectingelement 38 and further through auxiliary elongated element 118, and outthrough auxiliary elongated element proximal exit point 121. Thus, onlyone guidewire is used in the configuration shown in FIG. 3. This designprovides a single guidewire enclosure split into two sections—one at thedistal end and one at the proximal end of balloon 124—in order to reducethe profile of system 100 in the vicinity of balloon 124 duringintroduction of system 100 into a vessel. Guidewire 48, while positionedwithin distal connecting element 138 and auxiliary elongated element118, can serve as a focused force to help crack difficult lesions andmay also be used as a tracking guidewire for advancing system 100 intothe vessel.

Reference is now made to FIG. 4, which is a schematic illustration of asystem 200 for treatment of a vessel, in accordance with yet additionalembodiments of the present invention. The embodiment shown in FIG. 4 hasa reduced profile due to the use of a fixed wire balloon, and may beparticularly useful for smaller peripheral vessels such asinfrapopliteal vessels, for example. System 200 includes a mainelongated element 212 having a proximal end 214 and a distal end 216. Insome embodiments of the present invention, main elongated element 212 isa catheter shaft. A balloon 224 is positioned at distal end 216 of mainelongated element 212. Balloon 224 can be comprised of a variety ofdiameters, ranging from 1.25-10.0 mm, for example, and a variety oflengths, ranging from 10 mm to 30 cm, for example. Long balloons may beparticularly useful for treating peripheral lesions, which often havelong diseased portions. In the embodiment depicted in FIG. 4, balloon224 is a fixed wire balloon. In one embodiment, balloon 224 is a fixedwire balloon as is commonly known in the art. An example of such aballoon is the type used for the Ace™ Balloon Catheter of BostonScientific Corporation (Natick, Mass., USA). In another embodiment,balloon 224 is any balloon with a fixed wire attached thereto. System200 further includes an auxiliary elongated element 218 configured toreceive a guidewire 48 therethrough. Auxiliary elongated element 218 hasa proximal end 220 with a proximal exit point 221 for guidewire 48 and adistal end 222 with a distal exit point 223 for guidewire 48. In someembodiments, at least a portion of auxiliary elongated element 218 ispositioned within main elongated element 212 so as to reduce the outerprofile of system 200. Distal end 222 of auxiliary elongated element 218is proximal to balloon 224 such that guidewire 48, when positionedthrough auxiliary elongated element 218, exits distal exit point 223 andruns alongside and external to balloon 224. This configuration providesfor a focused force element alongside balloon 224, as will be describedfurther hereinbelow. In some embodiments, such as the one shown in FIG.4, auxiliary elongated element 218 is relatively short, extending 5-30cm, and in some embodiments approximately 20 cm. This configurationenables rapid exchange in cases when system 200 may need to be retractedand a different device reinserted over guidewire 48. In otherembodiments, auxiliary elongated element 218 may continue proximallyalong the entire length of main elongated element 212 for anover-the-wire configuration, such as described above with reference toFIG. 1A. In one embodiment, guidewire 48 positioned through distal exitpoint 223 forms a crotch point 246 at or near a proximal end of balloon224. The presence of a crotch point may be useful, for example, foranchoring system 200 within a side branch to avoid slippage within thevessel to be treated, or to provide for precise positioning of system100 at a bifurcation.

In some embodiments, main elongated element 212 is stiffer proximallythan distally. This may be accomplished, for example, by using a metalhypotube in the proximal portion and a polymer or other flexiblematerial in the distal portion. This configuration provides moreflexibility at the distal end to allow for easier maneuverabilitythrough tortuous vessels, while maintaining rigidity at a proximal endfor pushability. However, if the distal portion of main elongatedelement 212 is too flexible, it will be difficult to push through thevessels. Thus, system 200 further includes a core wire 228, whichprovides enhanced pushability of system 200 without significantlyreducing the flexibility of system 200. Core wire 228 is provided in theflexible portion, and may terminate at the stiff portion when no longerneeded for rigidity. In other embodiments, main elongated element 212 isrelatively flexible along all or most of its length, by using a flexiblepolymer or other flexible material to form main elongated element 212.In these embodiments, core wire 228 may run along an entire length ofmain elongated element 212 and may vary in diameter along the length soas to provide increased rigidity at proximal end 214. In someembodiments, the flexible shaft may also be braided or otherwisestrengthened to provide sufficient rigidity.

In embodiments of the present invention, core wire 228 has a portionpositioned within main elongated element 212, referred to herein asinternal core wire 230, and a portion positioned external to mainelongated element 212, referred to herein as external core wire 232. Forembodiments wherein main elongated element 212 is comprised of arelatively flexible distal portion and a relatively rigid proximalportion, internal core wire attachment point 244 is located at aninterface between the stiff proximal portion and the flexible distalportion, for example, a distal end of the hypotube. In embodimentswherein main elongated element is mostly or completely comprised offlexible material, internal core wire attachment point 244 is located atproximal end 214 of system 200. However, it should be readily apparentthat internal core wire attachment point may be located at any locationalong the length of main elongated element 212. Moreover, multipleinternal core wire attachment points 244 may be included. At a locationproximal to balloon 224, internal core wire 230 exits main elongatedelement 212 and becomes external core wire 232. This location isreferred to herein as a core wire exit point 242. In one embodiment,core wire exit point 242 is at a distal end of main elongated element212 (but in most cases proximal to balloon 224). In other embodiments,core wire exit point 242 is at other locations along main elongatedelement 212. Distal to core wire exit point 242, external core wire 232is positioned alongside balloon 224, and a distal end of external corewire 232 is attached to a distal tip 225 of balloon 224. Severalattachment or bonding locations provide transmission of forces throughthe length of the catheter, and thus enhance overall torquability androtatability. In particular, bonding can be done at any or all of thefollowing locations: at a distal tip of balloon 224, at core wire exitpoint 242, and at internal core wire attachment point 244. Additionalattachment points may be included as well. It should be noted that theuse of an internal core wire makes it possible to have a longer flexible(polymeric or other) portion or even a completely flexible shaft,enhancing overall flexibility of system 200. In some embodiments,external core wire 232 and fixed wire 240 are comprised of the samewire. In other embodiments, some or all of external core wire 232 andfixed wire 240 are separate pieces of wire which are connected at thedistal tip of balloon 224.

In all of the systems described above, a hydrophilic coating may beadded externally to provide ease of insertion.

Reference is now made to FIG. 5A and FIG. 5B, which are schematicillustrations of external core wire portion 32, 132, 232 in accordancewith embodiments of the present invention. As shown in FIG. 5A, externalcore wire portion 32, 132 or 232 is configured with a wire portion 60and a coil 34. Wire portion 60 includes a proximal wire section 62, amid-wire section 64 and a distal wire section 66. Proximal and distalwire sections 62 and 66 both have a diameter D1 which is greater than adiameter D2 of midwire section 64. Coil 34 is wrapped around mid-wiresection 64. When in position on system 10, mid-wire section 64 with coil34 runs alongside balloon 24. This configuration provides enhancedflexibility as well as gripping at the lesion so that slippage ofballoon 24, 124, 224 against the lesion is reduced. Moreover, in someembodiments, coil 34 is comprised of radiopaque material, and thus actsas a marker for positioning of system 10, 100 or 200.

Reference is now made to FIG. 5B, which is an illustration of externalcore wire portion 32 in accordance with another embodiment of thepresent invention. Core wire 32 is a wire having at least one radiopaquemarker 36 thereon. Multiple markers 36 may be used, and may be spaced atoptimal locations such as at a proximal end and a distal end of balloon24, for example.

Although external core wire portion 32 is positioned external to balloon24 when balloon 24 is in its inflated state, as shown in FIGS. 1A, 2, 3and 4, when balloon 24 is in its deflated state (i.e., during insertionof system 10 into the body), external core wire portion 32 may bepositioned within folds of balloon 24. Reference is now made to FIG.6A-6D, which are cross-sectional illustrations along line B-B of system10 showing external core wire portion 32, guidewire 48, trackingguidewire 49, and balloon 24 in its deflated state (FIGS. 6A and 6B) andits inflated state (FIGS. 6C and 6D). It should be readily apparent thatsimilar configurations are possible for systems 100 and 200 as well. Asshown in FIGS. 6A and 6B, when balloon 24 is in its deflatedconfiguration, external core wire portion 32 is positioned within foldsof balloon 24. If a guidewire 48 and/or tracking guidewire 49 arepresent, guidewire 48 and tracking guidewire 49 can be seen alongsideballoon 24. As shown in FIG. 6C, when balloon 24 is expanded, externalcore wire portion 32 is positioned alongside balloon 24. The externalposition of external core wire portion 32 with respect to balloon 24provides an area of focused force for cracking or breaking up hard ordifficult lesions. Guidewire 48 and tracking guidewire 49 may be used toprovide an additional area of focused force. In some embodiments,guidewire 48 is positioned at a rotational distance from external corewire portion 32 so as to provide multiple areas of focused force aroundsystem 10. For example, auxiliary elongated element 18 may be positionedapproximately 180 degrees from external core wire portion 32, orapproximately 120 degrees from external core wire portion 32 andapproximately 120 degrees from tracking guidewire 49, although it shouldbe readily apparent that many different rotational distances arepossible.

Reference is now made to FIG. 6D, which is a cross-sectionalillustration along line B-B, in accordance with another embodiment. Inthis embodiment, additional external core wires 33 and 35 are present aswell. Although shown with three external core wires, any suitable numberof core wires may be used. In one embodiment, core wire 28 is split intomultiple wires at core wire exit point 42, and the multiple core wiresare bundled together at distal end 16 of system 10. In an alternativeembodiment, multiple core wire exit points 42 are spaced around mainelongated element 12, and multiple core wires exit through the multiplecore wire exit points. They are then bundled together at distal tip 25of balloon 24.

Reference is now made to FIGS. 7A-7E, which are schematic illustrationsof the steps of a method of treating a vessel, in accordance withembodiments of the present invention. A vessel 300 having a lesion 302is accessed via tracking guidewire 49 as shown in FIG. 7A. Trackingguidewire 49 is backloaded onto system 10 by placing tracking guidewire49 through distal connecting element 38, and system 10 is advanced overtracking guidewire 49 to the vicinity of lesion 302, as shown in FIG.7B. Next, an additional guidewire 48 may be positioned through auxiliaryelongated element 18, and advanced until a distal end of guidewire 48 isdistal to balloon 24, as shown in FIG. 7C. In some instances, whenguidewire 48 is difficult to advance to this distal location, system 10may be advanced distally past lesion 302, such that distal exit point 23of auxiliary elongated element 18 is beyond lesion 302. Guidewire 48 isthen advanced through auxiliary elongated element 18. System 10 may thenbe pulled back proximally so that guidewire 48 and tracking guidewire 49are adjacent balloon 24 and are in a vicinity of lesion 302. Balloon 24is then expanded, as shown in FIG. 7D. Expansion of balloon 24 causesexternal core wire portion 32 to be released from within folds ofballoon 24. Expansion of balloon 24 further causes guidewire 48,tracking guidewire 49 and external core wire portion 32 to be pushed upagainst lesion 302 in three separate rotational positions around thevessel and the lesion. The presence of guidewire 48, tracking guidewire49, and/or external core wire portion 32 provides a focused force toenable the user to crack hard lesions at low pressure before balloon 24is fully inflated. Doing so allows vessel stretching to occur at a lowerstrain rate, thus minimizing the trauma associated with balloondilatation.

In some embodiments, auxiliary elongated lumen 18 may further be used toprovide an item or substance to the vessel. Reference is now made toFIG. 7E, which is a schematic illustration of system 10 positionedinside vessel 300. After the lesion has been cracked or pushed open viaballoon 24 and/or external core wire portion 32 and/or guidewire 48,and/or tracking guidewire 49, balloon 24 may then be deflated. In someembodiments, guidewire 48 is retracted to provide an open lumen fordelivery of an object or drug to vessel 300. Occlusion balloon 54 isinflated, blocking the portion of vessel 300 which is proximal toocclusion balloon 54. Then, a drug, contrast media or other treatmentdevice may be inserted through auxiliary elongated element 18 and usedto treat vessel 300. In some embodiments, after deflating balloon 24,system 10 is advanced past the lesion, occlusion balloon 54 is inflatedand treatment is provided to a portion of vessel 300 which is distal tolesion 302. In yet another embodiment, as shown in FIG. 1A, system 10does not have occlusion balloon 54. After deflating balloon 24, system10 is advanced past the lesion. Balloon 24 is reinflated at low pressureto occlude vessel 300, and treatment is provided to a portion of vessel300 that is distal to lesion 302. In some embodiments, ports 19 mayprovide additional access for treatment of the vessel by sprayingtreatment solution, for example.

In some embodiments, auxiliary elongated element 18 may be used tointroduce a “buddy wire” for tortuous vessels. The “buddy wire” conceptis known in the art, and involves introducing a secondary wire alongsidea catheter to help straighten out curved vessels and ease the way forthe catheter. However, by using a system such as the ones describedherein, the “buddy wire” may be introduced within the catheter,minimizing the risk of puncture of the vessel or entanglement of thebuddy wire with the catheter. Moreover, systems of the present inventionmay also be used to introduce a second wire for bifurcations, whereinguidewire 48 introduced through auxiliary elongated element 18 andtracking guidewire 49 may both remain in the vessel. When the system isremoved from the body, guidewire 48 is prevented from entanglement withtracking guidewire 49 since guidewire 48 is positioned within auxiliaryelongated element 18. Thus, any crossing over which may occur isautomatically straightened out during removal of system 10. Anadditional use of system 10 is in cases where a practitioner encountersa “false lumen”. That is, if tracking guidewire 49 encounters an areawhich is not a true lumen, an additional guidewire 48 may be introducedthrough system 10 and through the true lumen. System 10 may then beretracted proximally, and advanced over guidewire 48 to cross thelesion.

Reference is now made to FIGS. 8A-8C, which are schematic illustrationsof the steps of a method of treating a vessel, in accordance withembodiments of the present invention. A vessel 300 having a lesion 302is accessed via guidewire 48, as shown in FIG. 8A. Guidewire 48 isbackloaded onto system 100 by placing guidewire 48 through distalconnecting element 138, and further positioning guidewire 48 throughauxiliary elongated element 118, as shown in FIG. 8B. In someembodiments, an introducer is used to help place guidewire 48 intodistal exit point of auxiliary elongated element 118. The introducer maybe, for example, a mandrel having a female end, which is pre-loaded intoboth auxiliary elongated element 118 and distal connecting element 138.When guidewire 48 is backloaded into distal connecting element 138, theproximal end of guidewire 48 is positioned within the female end of themandrel. The mandrel may then be pulled back proximally, leadingguidewire 48 into auxiliary elongated element 118. Guidewire 48 is thuspositioned through both distal connecting element 138 and throughauxiliary elongated element 118, and exits through auxiliary elongatedelement proximal exit point 121, which may be relatively close toauxiliary elongated element distal exit point 123 for rapid exchange asshown in FIG. 8B, or may be at proximal end 114 of main elongatedelement 112 for an over-the-wire configuration. System 100 is advancedover guidewire 48, and positioned such that balloon 124 is adjacentlesion 302, as shown in FIG. 8B. It should be noted that external corewire 132 is not shown in FIG. 8B during insertion, since it is foldedinto balloon 24. Balloon 124 is then inflated, which pushes bothguidewire 48 and external core wire 132 up against lesion 302. Thepresence of guidewire 48 and/or external core wire 132 provides afocused force to enable the user to crack hard lesions at low pressurebefore balloon 124 is fully inflated. Doing so allows vessel stretchingto occur at a lower strain rate, thus minimizing the trauma associatedwith balloon dilatation.

Reference is now made to FIGS. 9A-9C, which are schematic illustrationsof the steps of a method of treating a vessel, in accordance withembodiments of the present invention. A vessel 300 having a lesion 302is accessed via guidewire 48. Guidewire 48 is backloaded onto system 200by placing guidewire 48 through auxiliary elongated element 218.Guidewire 48 exits through auxiliary elongated element proximal exitpoint 221, which may be relatively close to auxiliary elongated elementdistal exit point 223 for rapid exchange as shown in FIGS. 9B and 9C, ormay be at proximal end 214 of main elongated element 212 for anover-the-wire configuration. System 200 is advanced over guidewire 48,and positioned such that balloon 224 is adjacent lesion 302, as shown inFIG. 9B. It should be noted that external core wire 232 is not shown inFIG. 9B during insertion, since it is folded into balloon 224. Balloon224 is then inflated, as shown in FIG. 9C, which pushes both guidewire48 and external core wire 232 up against lesion 302. The presence ofguidewire 48 and/or external core wire 232 provides a focused force toenable the user to crack hard lesions at low pressure before balloon 224is fully inflated. Doing so allows vessel stretching to occur at a lowerstrain rate, thus minimizing the trauma associated with balloondilatation. Alternatively, instead of introducing a guidewire, fixedwire 240 is used to cross the lesion. In this embodiment, auxiliaryelongated element 218 may optionally not be included. Balloon 224 isthen expanded, and external core wire 232 provides the focused force. Ifauxiliary elongated element 218 is present, a guidewire 48 mayadditionally be introduced through auxiliary elongated element 218 toprovide additional focused force. These forces may be useful in treatinga variety of lesions, including those found at renal or peripheralvessels, and may be useful for procedures requiring high forces such asvalvuloplasty. It should be readily apparent that when auxiliaryelongated element 218 is included, it may also be used as a conduit toprovide objects, treatment drugs, contrast media, guidewires, etc. tothe vessel.

In some embodiments, the systems of the present invention may be used totreat vessels at a bifurcation. Reference is now made to FIGS. 10A-10C,which are schematic illustrations of the steps of a method for treatinga bifurcated vessel, in accordance with embodiments of the presentinvention. First, tracking guidewire 49 is introduced into the mainvessel 300, as shown in FIG. 10A. Next, system 10 is advanced overtracking guidewire 49 by backloading tracking guidewire 49 throughdistal connecting element 38, as shown in FIG. 10B. A guidewire 48 maythen be advanced through auxiliary elongated element 18 and into abranch vessel 304. The main vessel lesion 302 may then be treated byinflating balloon 24, while branch vessel 304 is protected in case ofplaque shift or additional lesion portions extending into branch vessel304. In alternative embodiments, system 100 is advanced over a guidewire48 by backloading guidewire 48 into both distal connecting element 38and auxiliary elongated element 18. After treatment of lesion 302 inmain vessel 300, guidewire 48 may be pulled back proximally andintroduced into branch vessel 304. The balloon is deflated, the catheteris retracted along the guidewire, and the system is introduced into thebranch vessel. The balloon may then be reinflated so as to compress thelesion in the branch vessel. In an alternative method, the guidewire isintroduced into the branch vessel, and the catheter is advanced over theguidewire past the bifurcation and into the main vessel. The main vessellesion is then treated by inflating the balloon and compressing thelesion. The balloon is deflated, the catheter is retracted, andintroduced into the branch vessel such that the guidewire is positionedalongside the balloon. Upon inflation of the balloon, the guidewire iscompressed into the lesion site, and provides a focused force to enablethe user to crack hard lesions at low pressure before the balloon isfully inflated. This alternative method is possible using system 200with fixed wire 240, since fixed wire 240 may be used to cross thelesion at the main vessel while guidewire 48 is positioned in the branchvessel.

While certain features of the present invention have been illustratedand described herein, many modifications, substitutions, changes, andequivalents may occur to those of ordinary skill in the art. Forexample, a catheter for uses other than expansion of a balloon and/ordelivery of a stent may be used with the device of the presentinvention, such as a catheter for drug delivery at an ostium, forcauterization, or for any other treatment. It is, therefore, to beunderstood that the appended claims are intended to cover all suchmodifications and changes as fall within the true spirit of the presentinvention.

1. A device for introduction into a vessel, the device comprising: amain elongated element having a main elongated element proximal end anda main elongated element distal end; a balloon positioned at the mainelongated element distal end; and a core wire attached to the device ata core wire attachment point, comprising an internal core wire portionpositioned in the main elongated element and an external core wireportion positioned distally with respect to the internal core wireportion and positioned in parallel relation and external to the balloon.2. The device according to claim 1, further comprising an auxiliaryelongated element having an auxiliary elongated element proximal end andan auxiliary elongated element distal end, the auxiliary elongatedelement distal end positioned proximal to the balloon.
 3. The deviceaccording to claim 2, further comprising a distal connecting elementpositioned at a distal end of the balloon to receive a guidewire duringuse, the balloon being pushed along the guidewire upon application of apushing force to the proximal end of the main elongated element.
 4. Thedevice according to claim 3, wherein the distal connecting element is ata rotational distance from the auxiliary elongated element, and whereinthe distal connecting element and the auxiliary elongated element are atrotational distances from the external core wire portion.
 5. The deviceaccording to claim 4, wherein the rotational distances are between 60and 120 degrees.
 6. The device according to claim 3, wherein the distalconnecting element is rotationally aligned with the auxiliary elongatedelement.
 7. The device according to claim 1, wherein the balloon is afixed wire balloon.
 8. The device according to claim 2, wherein theauxiliary elongated element is positioned at least partially inside ofthe main elongated element.
 9. The device according to claim 2, whereinthe device is an over-the-wire catheter and wherein the auxiliaryelongated element runs along an entire length of the device.
 10. Thedevice according to claim 9, further comprising an occlusion balloonpositioned proximal to the auxiliary elongated element distal end. 11.The device according to claim 2, wherein the auxiliary elongated elementproximal end is positioned at a point along the main elongated elementsuch that a guidewire placed through the auxiliary elongated element mayexit at the auxiliary elongated element proximal end for rapid exchange.12. The device according to claim 1, further comprising a distalconnecting element positioned at a distal end of the balloon to receivea guidewire during use, the balloon being pushed along the guidewireupon application of a pushing force to the proximal end of the mainelongated element.
 13. The device according to claim 1, wherein theexternal core wire portion further comprises a coil wrapped around atleast a portion thereof, the coil-wrapped portion being positionedadjacent to the balloon.
 14. The device according to claim 1, whereinthe external core wire portion comprises at least one radiopaque marker.15. The device according to claim 1, wherein the main elongated elementcomprises a flexible portion and wherein the internal core wire portionis positioned along an entire length of the flexible portion.
 16. Thedevice according to claim 1, wherein the main elongated elementcomprises a stiff proximal portion and a flexible distal portion,wherein the attachment point is at an interface between the stiffproximal portion and the flexible distal portion.
 17. The deviceaccording to claim 16, wherein the stiff proximal portion comprises ahypotube in a proximal portion of the main elongate element.
 18. Thedevice of claim 16, comprising additional attachment points at a distaltip of the balloon and at a transition of the internal core wire portionto the external core wire portion.
 19. The device of claim 1, whereinthe attachment point is at a distal end of the balloon.
 20. The deviceof claim 1, wherein the attachment point is at a proximal end of thedevice.